1. Field of the Invention
This invention relates to a bag-filter type small deodorizing and dust collecting apparatus for improving work environment in a foundry or the like which requires deodorization.
2. Description of the Prior Art
In the foundry or the like, a dust collector collecting and removing generated dust is installed as a solution to the dust. However, since the air discharged into the atmosphere has an unusual odor, a new problem of odor arises in the neighboring area.
To solve the problem, the air discharged from an air exhausting device into the atmosphere has been deodorized and desulfurized.
The dust collecting technology like this includes:
Patent Document 1, Publication No. 2006-122764;
Patent Document 2, Patent Publication No. 2002-35523; and
Patent Document 3, Patent Publication No. 2008-30010.
The dust collecting technology referred to in the above Patent Documents 1 and 2 is that a filter itself contains activated carbon, or quick lime is blown in for desulfurization purpose.
However, the filter containing the activated carbon has to be replaced frequently as the deodorization performance deteriorates. In the method of simply blowing the activated carbon or the quick lime, deodorization function can be fulfilled, however, when these substances are caught by the filter and are blown away (by backwashing or the like), the substances are only discharged, which is very inefficient.
Therefore, the invention provides for a reflux method in which the activated carbon and the quick lime are put into the bag-filter type dust collector, and the activated carbon and the quick lime falling from the bag filters are collected and put into the dust collector again.
According to the method, the activated carbon or the like can be reused, and the economic efficiency is improved.
The bag-filter type dust collector in Patent Document 3 is a large-scaled dust collector by which the dust in the whole foundry etc. is collected and its priority is primarily placed on a dust collecting function. Therefore, deodorization using the large-scaled dust collector requires a large amount of expensive activated carbon etc. In addition, although the odor can be removed from the air discharged out of the plant into the atmosphere, there remains a problem at the work field.
In other words, in the foundry for aluminum casting, aluminum die-casting or the like for example, using a core of a shell-mold etc. accompanying an odor, each molding machine generates the odor, and the problem that the frontline workers are exposed to the odor has not been solved.
In order to solve the problem, a small deodorizing and dust collecting apparatus, which can be installed near the molding machine is required.
In addition, the deodorizing property of the activated carbon itself etc. is degraded after long use, and at the same time, the deodorizing efficiency is degraded because the mixing ratio of the activated carbon etc. as the deodorizing powder is lowered due to the powder dust or the like which is sucked. Consequently, it is required to facilitate supply of new activated carbon and discharge of the old activated carbon.
Further, the conventional dust collecting apparatus needs to have a conveying device like a screw feeder to reflux the deodorizing powder, which raises the manufacturing cost.